Collection Member Declarations

In a one-to-many relationship, the multiple
side consists of a collection of entities. An identification variable can
represent a member of this collection. To access a collection member, the
path expression in the variable’s declaration navigates through the
relationships in the abstract schema. (For more information on path expressions,
see the following section.) Because a path expression can be based on another
path expression, the navigation can traverse several relationships. See Traversing Multiple Relationships.

A collection member declaration must include the IN operator,
but it can omit the optional AS operator.

In the following example, the entity represented by the abstract schema
named Player has a relationship field called teams. The identification variable called t represents
a single member of the teams collection.